Targeted inhibition of E. coli adhesion using antisense oligonucleotides: an approach to combat bacteria via CsrB targeting.

Biofilm is the most prevalent form of bacterial existence in natural environments and is associated with serious health conditions such as diarrhea and kidney failure. The carbon storage regulator A (CsrA) protein, along with its small regulatory RNAs CsrB and CsrC, plays a pivotal role in key cellular processes, including biofilm formation, motility, carbon metabolism, iron homeostasis, and stress response. In this study, a novel antisense oligonucleotide (ASO) was specifically designed to target and silence the csrB gene in Escherichia coli. The ASO was delivered using polyethyleneimine (PEI), and its efficacy was evaluated through gene expression analysis, colony-forming unit (CFU) assays, and crystal violet staining. Quantitative real-time PCR revealed a significant reduction in csrB and csrA expression in the treated O42 strain (p = 0.004 and p = 0.013, respectively), as well as a notable decrease in csrB expression in the O157 strain (p = 0.041). Furthermore, biofilm formation and bacterial adhesion were significantly reduced in the treated O42 strain (p = 0.046 and p = 0.028, respectively). These findings suggest that antisense oligonucleotides targeting small regulatory RNAs such as csrB may offer a promising therapeutic strategy for controlling biofilm-associated infections by disrupting key regulatory pathways in bacterial adhesion and biofilm development.